This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Our goal is to define the active conformation (structure) of the membrane-bound complex of blood coagulation factors essential for the aniticoagulant pathways of blood hemostasis. Our approach is to organize them helically on the surface of lipid nanotubes and define its membrane-bound structure by Cryo-EM and image reconstruction.